Bearing for air propeller shafts



Dec. 151,-61942. F, NALLINGER Erm.

BEARING FOR AIR PROPELLE'R SIAFTS Filled April 18. 1940 '/l/Illlll/l.

- v"UNITED STATES PATENT. OFFICE i assumo ron Aritrnum slums Fm. N stumm, ma alters ma, st ttgm- Cannstatt Germany; vestodin th'el Allen 'Property Custodian A u o ru 1s mo, sum No. 330,324

Pp In (lixergiany IIesember 21, 1938 7 Claims. (Cl. 64I-1) whereby said motors respectively theircylinders are mounted upon a common crank casing making an angle with each other. According to the invention the air'propeller shafts are supported at one end swingingly and at the other end yieldingly and further supported in a sliding tube transmitting the tensile andshearing forces of the air propeller for instance tothe motorand gear block. l

The invention has first the object, particularly in air craft driving mechanisms, to protect thinwalled parts or in a determined direction relatively not very strong construction parts against hsileand shearing stresses or transverse shocks and -vibrations and to transmit these forces to such parts adapted to resist these stresses. As such a part may serve for instance the driving block.

Secondly the object of withstanding the use of motors of a yieldingly mounted motorand driving unitf or of in itself yielding parts serving for supporting the air propeller shaft, to ensure an unconstrained driving also when larger deformations or stronger vibrations of the yieldingly supported driving mechanism occur.

The sliding tube serving to support the air propeller shaft is in this case in a suitable manner. swingable in the block of the driving unit and yieldingly supported in the hull body or the like construction part. g

The mounting of the motor cylinders upon a common crank casing has the advantage of a compact construction and a simple support of the driving parts situated in front of the motors and driving the air propeller shafts rotating in opposite direction.- Moreover the dangerous displacements of both main driving shafts with respect to each other are prevented and the driving unit `can be hung in a simple manner in the air craft.

the invention is, not- In `the drawing a diagrammatical form of execution according to the invention is shown. Herein is:

Fig. 1 a multiple motor two in opposite direction rotating air propeller shafts in length sectional view;

Fig. 2 the construction of the two parts of the and 2 are mounted upon the common crank casing 2 making an angle with each other. Both outsidely lengthened crank shafts 4 and I are provided with free-wheel couplings 6, 1 as well as with gear wheels 8, 3 and I0, I I respectively.

'll'he gear wheels 8, III engage the centrally mounted gear wheel I2 connected to the shaft yieldingly supported I3. The inner air propeller shaft I4 is connected to the shaft I3 by an elastic-coupling I5. Both gear wheels 9, II are driving through transmitting wheels I3, I9 the centrally mounted gear wheel 2l oi' the outer alt propeller shaft I1 rotating in opposite direction. The said shaft .1

is coupled to the centrally mounted shaft 23 by an elastic coupling 22, said shaftbeing also connected to the gear wheel 2l. 'I'he sliding tube 24, being adjustable in length direction for instance by an adjusting ring 20, is supported in an articulated bearing 24' of the gear casing lid. The yielding support of the sliding tube 24 is eiiected for instance by rubber rings 25 and 26.

It is self-evident that the arrangement may also be so, that the driving motors are provided with separate crank casings.

driving mechanism for air propeller shaft in length sectional view, and

Fig. 3 a cross-sectional view through the line III-III of Fig. 2.

The cylinders of both combustion engines I The outer air propeller shaft I1 bears unyieldingly upon the.inner air propeller shaft I3/ I4 at the end directed to the motor at 21 and at the end directed to the air propeller at 28. The outer air propeller shaft is in its turn unyieldingly supported at the end directed to the propeller in the sliding tube 24 at 29. As well as the bearing length of the sliding tube 24 is adjustable at 20, also the bearing length of the air propeller shafts I4, I1 may be adjustable at the hinging spots I5, 22.

As coupling within the air propeller shafts suiiices according to Fig. 1 a simple cam gear with avsmall clearance in order to allow a swinging movement of the outer part of the shaft'.

A shaft coupling as shown in Figs. 2 and 3 has proved to be very advantageous. According to this'form of execution the end of the air propeller shaft directed to the coupling point is at 30 cylindrically turned out and on the, contrary the end of the shaft I3 has a ball-shaped smaller end SI, ntting with its largest outer diameter exactly in the part l30 and ensures in this manner an equal axial position of -both shafts I3 and I4. The end ofthe air propeller shaft I4 is extending about the length of the part 30 provided with a 'gear32 and the corresponding end of the grooved la containing a spring ring 31. The ring 31 prevents the coupling ring from displacing axially with respect to the gear 32 and 33.

Between the inner gear 35 of the coupling ring and the gears 32, 33 is a small clearance enabling a swinging movement of the shaft Il around the ball-shaped part 3| of the shaft I3 as far as the elasticity of the yielding support 23 allows. The swinging movement of the air propeller shaft Il takes place substantially about a centre M, forming at the same time the centre for the radius of curve of the swinging bearing 24'.

By the arrangement according to the invention particularly by the described support of the sliding tube respectively of the air propeller shaft is obtained that when the'yieldingly supported driving unit swings, the air propeller shafts to-V gether with the sliding tube is allowed to swing.

about the centre M of the swinging bearing 24T v and clamping tensiles will not engage the air propeller shaft.` The rubber bearing 25 prevents hereby at the same time an undamped transmission of the vibrations and shocks to the relative weak hull lining or bracing. vAt the same -time the yielding support 25 enables, however,

also an axial displacement of the 'sliding tube 24 in such avmanner that said sliding tubev 24 trans' mits the shearing tensiles to the swing gear 24',

where the same are taken up by the gear casing 38 and the crank casing 3.

What wel claim -isz 1. In an aircraft having propellers rotating in opposite directions, a fuselage and a motor asy sembly including a plurality of driving shafts,

the combination of a plurality of propeller shafts extending coaxially within one another, coupling meansvconnecting the inner end of each propeller shaft with the outer end of-a corresponding driv'- ing shaft so as to transmit Vthe torque of the driving shaft to the propeller shaft and to permit slight pivotal movements of the latter relative Y to the former, an elongated member surrounding the propeller shafts, means including a part rigid with ythe motor assembly to pivotally support the inner end of said elongated4 member securev against axial displacements, and means for elastically mounting the outer end of said elongated member in the fuselage.

means including a part rigid with the motor assembly to pivotally support the inner end of said tubular member secure against axial displacements, and means forelastically mounting the outer end of said tubular member in the fuselage. l

6, In an aircraft having propellers rotating in opposite directions, the combination of a first hollow driving shaft, a second driving shaft coaxial with and extending within said hollow drivingA shaft, a first hollow propeller shaft substantially aligned with said hollow driving shaft, a second propeller shaft coaxial with and extending through said hollow propeller shaft and substantially aligned with said, second driving shaft, the inner end of each propeller shaft being provided with a cylindrical recess, the outer end of each driving shaft being tapered on a. substantially spherical curvature and fitting with its spherically tapered'end into the cylindrical recess of the corresponding propeller shaft, coupling means connecting the inner end of each propeller shaft to the outer end of the corresponding driving shaft so as to transmit the torqueofthe driving shaft to thepropeller shaft and to permit slight pivotal movements of the latter relative to f the former, and bearing means elastically supporting the outer ends of said propeller shafts.

'1. In an aircraft-havingpropellers rotating in opposite directions, a fuselage and a motor assembly, the combination of a rst hollow driving shaft coupled to the motor assembly, a second driving shaft coupled toY the motor assembly, said surrounding said propeller shafts, bearing means 2. A combination, as claimed in claim 1, in-

cluding bearing means for the outer ends of said propeller shafts, said bearing means being mounted in saidy elongated member and adaptedv to transmit tensile stresses and pressure stresses to the latter.

`3. A combination, as claimed in claim 1, in-

cluding means for elastically supporting vthe pivoted end of said elongated member on the fuselage.

4. A combination, as claimed in claim 1, including means to vary the length of said elongated member.

5. In an aircraft having propellers rotating in y opposite directions, a fuselage and a motor assembly, the combination of a'flrst hollow driving shaft coupled to the motor, assembly, a second driving shaft coupled to the motor assembly, said second driving shaft being coaxial with and ex.- tending within said hollow driving shaft, a first hollow propeller shaft, a second propeller shaft coaxial with and extending through saidhollow propeller shaft, coupling' means connecting the inner end of each propeller shaft to the youter for the outer ends of said propeller shafts mounted in said tubular member, means for elastically supporting the outer end of said tubular member in the'fuselage, means including' a part rigid with the motor assembly to support the inner end of said tubular member for universal pivotal move-l ments about an imaginary pivot point disposed in the axis vof said shafts, and coupling means connecting the inner end of each propeller shaft with the 'corresponding driving shaft so as to transmit the torque of the driving shaft to the propeller shaft-and to permit slight pivotal moveof the latter relative to the former, the 'inner end of each propeller shaft being provided with a cylindrical recess, and the outer end of,- each-driving shaft being tapered on a substantially sphericalcurvature having its center coinciding with said imaginary pivot point, each drivingshaft fitting with its spherically tapered end into the cylindrical recess of the corresponding propeller shaft.

' FRITZ NALLINGER.

ALBERT- FRIEDRICH. 

